﻿/************************************************************************

   Extended Silverlight Toolkit

   Copyright (C) 2010-2012 Xceed Software Inc.

   This program is provided to you under the terms of the Microsoft Public
   License (Ms-PL) as published at http://extendedsilverlight.codeplex.com/license

   Please purchase a commercial version of this toolkit if you are using
   it in a commercial product. The commercial versions support the project,
   and also include more features for each control, priority support,
   source code, updates, removed watermark, and a proprietary license.

   Visit http://xceed.com and follow @datagrid on Twitter.

  **********************************************************************/

using Xceed.Silverlight.Data.Utils;

namespace Xceed.Silverlight.Data
{
  internal class DataSourceChangedEventManager : SLWeakEventManager
  {
    static DataSourceChangedEventManager()
    {
      if( DataSourceChangedEventManager.Instance == null )
      {
        DataSourceChangedEventManager.Instance = new DataSourceChangedEventManager();
        SLWeakEventManager.SetCurrentManager( typeof( DataSourceChangedEventManager ), DataSourceChangedEventManager.Instance );
      }
    }

    private DataSourceChangedEventManager()
    {
    }

    public static void AddListener( INotifyDataSourceChanged source, ISLWeakEventListener listener )
    {
      DataSourceChangedEventManager.Instance.AddListenerProtected( source, listener );
    }

    public static void RemoveListener( INotifyDataSourceChanged source, ISLWeakEventListener listener )
    {
      DataSourceChangedEventManager.Instance.RemoveListenerProtected( source, listener );
    }

    protected override void StartListening( object source )
    {
      INotifyDataSourceChanged dataSourceChanged = ( INotifyDataSourceChanged )source;

      dataSourceChanged.DataSourceChanged += this.OnDataSourceChanged;
    }

    protected override void StopListening( object source )
    {
      INotifyDataSourceChanged dataSourceChanged = ( INotifyDataSourceChanged )source;

      dataSourceChanged.DataSourceChanged -= this.OnDataSourceChanged;
    }

    private void OnDataSourceChanged( object sender, DataSourceChangedEventArgs e )
    {
      DataSourceChangedEventManager.Instance.DeliverEvent( sender, e );
    }

    private static DataSourceChangedEventManager Instance;
  }
}
